Hi Sandiliya,
Thank you for your interest in Syncfusion Products.
While adding more than one node to the TreeViewAdv control, calling the BeginUpdate and EndUpdate method will improve performance of the control. And also setting SuspendExpandRecalculate property to true will also improve the performance of the TreeViewAdv. Please refer to the below online tutorial that illustrates this:
http://help.syncfusion.com/ug_71/toolswin/TreeViewPerformance.htmlPlease let me know if any concerns.
Regards,
Fathima